1. Field of the Invention
The present invention relates to a toner resupply device, more particularly to a toner resupply device for resupplying toner from a hopper to a developing device, and an image forming apparatus provided with the toner resupply device.
2. Description of Related Art
An electrophotographic image forming apparatus, such as a printer, a copying machine or the like, an electrostatic latent image forming on a photoreceptor is developed with toner to turn into a toner image, and the toner image is transferred to a recording paper directly or via an intermediate transfer medium. This kind of image forming apparatus has a toner resupply device that stores toner in a hopper, and the toner is resupplied from the hopper to the developing device on a timely basis so as to compensate for the consumed toner.
In the toner resupply device, as a structure for detecting the amount of toner stored in the hopper, conventionally, a detector plate and a douser are arranged integrally such that the detector plate and the douser move up and down with changes in the surface level of the toner stored in the hopper, and the phase (the upward or downward pivot) of the douser is detected optically by a toner sensor. A shaft, which has a groove in its tip portion, is stuck in the douser, and the detector plate is fitted to the groove via a flexible fixing plate. There is formed a space between the groove made in the shaft and the detector plate, and the fixing plate is fitted in the space. In order to ease assembly of the fixing plate, it is necessary that the width of the groove made in the shaft is greater than the thickness of the fixing plate.
Making the width of the groove greater than the thickness of the fixing plate, however, will cause a problem that the shaft slants. The slant of the shaft will incur malfunction of the douser, which works with the detector plate, thereby resulting in an error in detecting the remaining amount of toner.
Japanese Patent Laid-Open Publication No. 2009-52738, which relates to a drive transmitting device, discloses that a spacer is fitted between a cut-off surface of a rotary shaft and an inner circumferential surface of a bearing so as to prevent a slip and misplacement of the rotary shaft. However, this will increase the number of components.